【Qt】QChart折线图

2024-09-01 11:52

文章标签 qt 折线图 qchart

本文主要是介绍【Qt】QChart折线图，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

引言

Qt绘图（Qt Charts）基于Qt的Graphics View架构，其核心组件是QChartView 和 QChart

QChartView是显示图标的视图，基类为QGraphicsView
QChart的基类是QGraphicsltem
可以看作是视图和数据分离，即ViewModel

QChartView

QChartView 是一个独立的小部件，继承于 QGraphicsView 类。它可以直接在用户界面中显示图表。这使得在应用程序中集成图表变得简单，而无需复杂的图形场景设置。

QChart

QChart是继承于QGraphicsWidget，可以在QGraphicsScene上显示，用来管理图表中的数据、图例、坐标轴等。

示例

// .h
#ifndef __WIDGET_H__
#define __WIDGET_H__#include <QtWidgets/QWidget>class Widget : public QWidget
{
public:Widget();~Widget();public:void createLineSeries(const std::pair<QString, std::vector<int>>& pair);private:class Impl;std::unique_ptr<Impl> impl_;
};#endif // __WIDGET_H__// .cpp
#include "Widget.h"#include <QtCharts/QLineSeries>
#include <QtCharts/QChartView>
#include <QtCharts/QChart>
#include <QtCharts/QValueAxis>#include <QVBoxLayout>#include <algorithm>
#include <vector>QT_CHARTS_USE_NAMESPACEclass Widget::Impl
{
public:Impl();~Impl() = default;public:QChart *chart_ = nullptr;
};Widget::Widget():QWidget(),impl_(std::make_unique<Impl>())
{setFixedSize(1700, 800);setWindowTitle(u8"亮度对比折线图");//创建图表框架QVBoxLayout *lay = new QVBoxLayout;setLayout(lay);impl_->chart_ = new QChart();impl_->chart_->legend()->setAlignment(Qt::AlignRight);QChartView *charView = new QChartView(this);charView->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);charView->setChart(impl_->chart_);lay->addWidget(charView);
}Widget::~Widget()
{
}void Widget::createLineSeries(const std::pair<QString, std::vector<int>> &pair)
{QLineSeries *series = new QLineSeries();series->setName(pair.first);for (int i = 0, sz = pair.second.size(); i < sz; i++){series->append(i, pair.second[i]);}impl_->chart_->addSeries(series);//impl_->chart_->createDefaultAxes();QValueAxis *axisY = new QValueAxis;axisY->setRange(50, 200);axisY->setTitleText(u8"像素值");axisY->setLabelFormat("%i");impl_->chart_->addAxis(axisY, Qt::AlignLeft);QValueAxis *axisX = new QValueAxis;axisX->setRange(0, pair.second.size());axisX->setTitleText(u8"序号");axisX->setLabelFormat("%i");impl_->chart_->addAxis(axisX, Qt::AlignBottom);series->attachAxis(axisX);series->attachAxis(axisY);auto allAxisX = impl_->chart_->axes(Qt::Horizontal);auto allAxisY = impl_->chart_->axes(Qt::Vertical);for (const auto it : allAxisX){it->hide();}for (const auto it : allAxisY){it->hide();}(*allAxisX.begin())->show();(*allAxisY.begin())->show();update();
}Widget::Impl::Impl()
{
}